1. Technical Field
The subject invention relates to monoclonal antibodies (e.g., 8F5 and 8C5) that may be used, for example, in the prevention, treatment and diagnosis of Alzheimer's Disease or other neurodegenerative disorders.
2. Background Information
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by a progressive loss of cognitive abilities and by characteristic neuropathological features comprising amyloid deposits, neurofibrillary tangles and neuronal loss in several regions of the brain see Hardy and Selkoe (Science 297, 353 (2002); Mattson (Nature 431, 7004 (2004). The principal constituents of amyloid deposits are amyloid beta-peptides (Aβ), with the 42 amino acid-long type (Aβ1-42) being the most prominent.
In particular, amyloid β(1-42) protein is a polypeptide having 42 amino acids which is derived from the amyloid precursor protein (APP) by proteolytic processing. This also includes, in addition to human variants, isoforms of the amyloid β(1-42) protein present in organisms other than humans, in particular, other mammals, especially rats. This protein, which tends to polymerize in an aqueous environment, may be present in very different molecular forms.
A simple correlation of the deposition of insoluble protein with the occurrence or progression of dementia disorders such as, for example, Alzheimer's disease, has proved to be unconvincing (Terry et al., Ann. Neurol, 30. 572-580 (1991); Dickson et al., Neurobiol. Aging 16, 285-298 (1995)). In contrast, the loss of synapses and cognitive perception seems to correlate better with soluble forms of Aβ(1-42) (Lue et al., Am. J. Pathol. 155, 853-862 (1999); McLean et al., Ann. Neurol. 46, 860-866 (1999)).
Although polyclonal and monoclonal antibodies have been raised in the past against Aβ(1-42), none have proven to produce the desired therapeutic effect without also causing serious side effects in animals and/or humans. For example, passive immunization results from preclinical studies in very old APP23 mice which received a N-terminal directed anti-Aβ(1-42) antibody once weekly for 5 months indicate therapeutically relevant side effect. In particular, these mice showed an increase in number and severity of microhemorrhages compared to saline-treated mice (Pfeifer et al., Science 2002 298:1379) A similar increase in hemorrhage was recently also described for very old (>24 months) Tg2576 and PDAPP mice (Wilcock et al., J Neuroscience 2003, 23: 3745-51; Racke et al., J Neuroscience 2005, 25:629-636). In both strains, injection of anti-Aβ(1-42) resulted in a significant increase of microhemorrhages. Thus, a tremendous therapeutic need exists for the development of biologics that prevent or slow down the progression of the disease without inducing negative and potentially lethal effects on the human body. Such need is particularly evident in view of the increasing longevity of the general population and, with this increase, an associated rise in the number of patents annually diagnosed with Alzheimer's Disease. Further, such antibodies will allow for proper diagnosis of Alzheimer's Disease in a patient experiencing symptoms thereof, a diagnosis which can only be confirmed upon autopsy at the present time. Additionally, the antibodies will allow for the elucidation of the biological properties of the proteins and other biological factors responsible for this debilitating disease.
All patents and publications referred to herein are hereby incorporated in their entirety by reference.